Maybe dumb question, but are borescopes like "EndoSnake" useful for semi-auto pistol barrels?, or not even worth it? Any better than just holding the barrel up to a light source? If I got one like the Lyman BoreCam for my long guns, is that useful for pistol barrels as well? I don't see why not, but just want to make sure I'm not overlooking any issue. Thanks.

In general unless you have a 90 degree mirror on the endoscope (a few have them, but not most, as far as I've seen), you're not going to get a lot of detail. Enough to tell if your cleaning regimen is working, perhaps, but not a lot more than that.

A true borescope (or an endoscope with a 90 degree mirror) will make it possible to see flaws in the rifling, throat/rifling erosion, etc. The bad thing is that you usually can't do anything about those short of replacing the barrel.

Yeah I guess it was a dumb question. Bore scope useful for long guns but not necessary for a pistol. Convinced not to waste money on an EndoSnake. Anyway, would be nice to include a pic of a pistol bore when posting for sale here on CG. Its impossible with just a cell phone camera.